Variable delivery pump or motor



Dec. 28, 1937.

K. BENEDEK 2,103,314

VARIABLE DELIVERY PUMP OR MOTOR Filed Dec. 51, 1935 2 Sheets-Sheet 2 V/////////////; 3] 55 1 5 5/ I W//////////////% 53 T151 E5 -4 0 4 o o 0 v0 0 50 0 is 5 A 6 a; Z 19 19 Z! O 10 Z O O o o I 61 O o o o O 5/ J6 34 55 Ema/whorl 5 I T- 57 2M 15 2 3% Patented Dec. 28, 1937 UNITED" STATES PATENT ol-"Pics aioam vaamsm nnuvr-zay rum on. Mo'roa El ni x. Benedek, Brien-us, Ohio Application December 31, 1 935, Serial No. 56,954 2 Claims. (c1. roe-161) This invention relates to pumps or motors of the radial piston type in which the piston actuating reactance ring is in floating driven relationship with respect to the rotating pistons and cylinders.

In the type of pumps hereinabove referred to the pistons are actuated by cross pins engaged at each side of the piston head in a floating reactance support. In such bly under high hydraulic radial piston load and during the pressure cycle of the piston and cylinder assembly'respectively, the piston cross head will yield elasticallyin the direction of load permitting the fluid medium to expand slightly until new equilibrium is reached between the elastic cross pin and the elastic pressure fluid. In'such instances it is obvious that. the plurality of radial pistons when rotating at substantially high speeds and making during each revolution a. pressure stroke and a suction stroke, respectively, the elastic deflection of the cross pins will cause an elastic impulse tothe elastic fluid conflned between the pressure pistons and the pressure port of the pintle. Assuming for the purpose of illustration. a pump workingv under 3000 pounds per square inch operating pressure'with 7 pistons and at 900 R. P. M. It will be obvious that during each revolution 7 elastic impulses will be transmitted to the resultant flow of the pump delivery eflected by 3 or 4 pressure pistons respectively, which will be'imparted to the pressure port of the pump. At 900 R. P. M. it is obvious that the working fluid will receive about 15 periodic impulses due to cross head deflections and subsequent expansion of the pressure fluid in. each second, which results in substantial noise and vibration.

One object of this invention the pumps hereinabove referred to a piston actuating reactancering, which will support the hydraulic piston load directly, in the zone of the working reaction and thus to eliminate noise and vibration by eliminating the deflection of the cross pins.

A further object is to combine a radial reoiproe eating piston actuating head with a central radial flange provided inthe zone of the pistons and working reactance respectively and with a piston actuating cross pin respectively, in such a manner that a floating reactance ring will support said cross pin directly in the zone of the working reaction and throughout the entire length of the pin.

A further object is to provide a sell. aligning floating connection between the outer ends of the pistons and said radial enlarged piston actuating heads.

variable delivery piston actuating assemline 2-2 in Fig.

is to provide for A further object is to provide secondary piston actuating means snugly arranged at each side of the guide flange of the cylinder barrel and the" associated piston head for the purpose of actuating the cross pins during suction periods-oi the 5 piston only. A further object is to provide anti-friction connection between said secondary piston actuating means and the head actuating cross pins in a novel manner. a A

A further object is to provide a novel bearing structure or support which will engage directly the head actuating cross pins or primary thrust means and the axially spaced cross pin actuating secondary rings respectively. 15.

-A further object is to provide a rigid bearing structure for the rot ry support of the floating piston actuating reactance.

Further objects and advantages will be described in connection with the drawings forming 20 a part of the following specifications.

In the drawings:--

' Fig. l is a central longitudinal sectional view of the pump disclosed for the p rpose oi illustration, certain parts being shown in elevation.

Fig. 2 is a transverse sectional view taken on 1, showing the rollers 01' the reactance bearing support as well as certain pistons in elevation instead of in section.

Fig. 3 is an axial sectional form of rolling thrust pin.

Fig. 4 is a cross secti nal view oi the pin illustrated in Fig. 3.

The pump'disclosed for illustration comprises a central cylindrical valve I. having a rigid support in the casing I0. The supported portion of the pintle as at l is pressed in the casing, in order toobtain for the active pintle portion 2 an accurate'position for the pintle in assembly. The stationary member 30 of the reactance support 40 32 is guided in a cylindrical portion or the casing 30, not shown in the drawings. ,It is imperative to mount the pintle I absolutely concentric with the cylindrical portion of the casing for the reason of supporting and confining the reactance support 32 and the reactance stator 36 respectively to parallel positions in every adjusted relatlve position between the pintle and reactance. To obtain such accurate assembly I finish machine the internal face 01' the radial wall of the casing, as at 30c, as well as at 38b to provide'accurate supporting surfaces for the casing, and bore a hole in the center of the radial wall for the large portion of the pintle I. In order to-obtain a rigid as well as hydraulically sealed connection view of a modified 0 for the external ports 5 and 6 respectively, of the pintle, I finish the bore 48c for the pintle in the hub portion of the case 38 to a dimension slightly smaller than the diameter of the large pintle portion I. -In order'to eliminate the tipping of the pintle in bore 380 of the casing, I propose to use a novel method of assembly which will eliminate expensive fixtures for the conven- "tional pressing in operation used heretofore. It

hardened nitralloy pintle, it is obvious that a very hard pintle shank having a larger diam eter than the bore in which we intend to press it in, it will act as a broaching tool and will enlarge the bore instead of stretching it for the purpose of an adequate press fit connection. It willbe noted further'on that it is imperative to seal the ports 5 and 6 against leakage during pressure periods of the reversible ports as well as against air suction during suction periods. In order to solve all the coordinated problems of a sound hydraulic connection at this point I "provide a shrink fit connection by either reducing the diameter of the shank portion l of the pintle or by expanding the'bore of the associated hub 380 by heat subtraction or by heating the same respectively.

The firstmethod comprises the application of such cooling means as dry ice, or the equivalent, which can be easily arranged in an isolated pot of such dimensions which will allow the introduction of thepintle for a certain length of time to lower its temperature below the shop temperature. It is required a shrinkage equivalent to several thousandths of an inch for the shrink fit. The method thus will comprise of keeping the casing of body 38 on shop temperature, the pintle in a refrigerator, dropping the pintle into its coacting bore in the right position and keeping it there undisturbed until the pintle will assume the shop temperature. It will then be noted that the high-finished bore of the body 38 will receive and grip the highly ground and polished pintle shank i into a smaller hole without tipping or cuttingwhichwould occur by pressingin operation. A

The cylinder barrel I3 is mounted at both ends in the casing on antifriction means 24 and 25 respectively. The antifriction means 24 and 25 comprise combination radial load and axial thrust complete bearing assemblies, including inner races 22 and 23 and outer races 26 and 21 respectively. It will be seen that due to the accurate alignment of the pintle in the casing it will be relatively easy to obtain concentricity be-.

tween the bore of the barrel and the shrink fitted pintle. The cylindrical portion of the casing preferably is made integral with the pintle supporting end of the housing. Thus there is 'all necessary requirements provided for accurate machining as well as assembly of the various portions of the casing in order to obtain coaxial relationship between bearing means 24 and 25 and casing thereby between the rigid pintle and the coacting barrel l3.

The barrel is provided with supporting flange l4 at the supported portion of. the pintle where- 'as at the opposite end it is provided with an extension portion as at ii in order to rigidly secure an impeller shaft ll thereto. Preferably at this end the barrel is provided with a tapered hole or. bore 8, coaxial with the pintle to receive a conical portion as at I of impeller shaft II. A splined or keyed connection for driving torque transmission is provided as at 9, whereas the axially rigid relationship between the impeller II and the engaging portion of the barrel I5 is further assured by lock nut l2. For this end the impeller shaft is threaded'as at III to receive the threaded nut 12. The nut may be further secured against rotation or movement with respect to the coacting abutment of the barrel by appropriate axial set screw not shown in the drawings. It will be noted that a rigid and sealed connection between the impeller.:connection I and the associated barrel end l5 will be necessary in order to prevent the escape of the slip fluid from the cylinders, between pintle 2 and coacting barrel and force the slipfluid to work backwards toward the opposite end of the pintle and barrel, and thereby cut the amount of fl'ective slip to one half of the normal conventional slip.

In order to sustain the thrust forces imposed upon the adjacent ends of the pintle 2 and impelling means I, it is necessary for the bearing means 25 to have suificient thrust capacity outside of its radial load capacity.

The cylinder barrel I3 is further provided with a plurality of radial cylinders as at IU. Each cylinder i8 is provided with a radial port II for the purpose of communication between the cylinder and the coacting ports 3 and 4 of the pintle 2 during rotation. Each cylinder I8 is provided with a radial piston [9. This piston l9 has further provisions, as hereinafter will be seen in order to associate with an enlarged piston actuatin head 20. Piston actuating head 20 is primarily guided in an appropriate radial flange as at ii in order to provide rolling frictional drlving'-1'elationship between the barrel i3 and an associated rotary assembly comprising a cylindrical ring support as at 32 and associated secondary sup-' port rings as at 29-29.

The piston proper I! is provided with a spherical thrust head as-at |9b in order to engage concentrically a coacting straight faced bottom 20b of the head 20. It will be seen that a radial bore provided in the head 20 which has slightly greater diameter than the piston itself, has a fiat bottom as at 20b so that at all times the anced pressure oil film will be provided in the small capillary working clearance space between pistonv l9 and cylinder bore l8 in such a manner that no friction or wear will take place due tog;-

the lack of misalignment or excessive transverse pressure therebetween. Thus it will be noted that in case of large power units where each piston and cylinder have to develop considerable horsepower, such provisions for emcient cooperation are important.

cooperate with the neck portion l9a oi the piston 5 I3 in order to receive a spring member as at 2|,

in order to actuate the piston l9 during suction stroke. It will be seen that the neck portion of the piston I30, has such diameter that the spring member 2| may be pressed in entirely into the 10 groove of said neck portion so that the outside diameter of the spring 2! will be equal, or less to the bore diameter of the receiving hole of head 20. In this manner by compressing the spring 2l snugly about the neck portion l9a. of the piston I9 it will be possible to lntroducethe piston into. the coacting hole of the head. Upon relieving the spring it will automatically expand and press against the'circular groove of the head in such a manner that suflicient projection is left 20 in order "to engage the shoulder of the neck groove I9a. In this manner a floating connection will beprovided between a large driving head 20 and the piston l9. The flange l6 of the cylinder barrel l3 will engage the working side walls 20a of the heads, for guiding and torque transmission. The guiding will take up the transverse forces resulting from the nature of the load transmission between a cylindrical support 32 and a coacting radial thrust head 20 and its associated means.

' The radial thrust head 20 is further provided with a cylindrical bore as at 20d in such a'manl ner that the thrust pin which is received in this .thrust bore will be mounted on its thrust trans- I mitting side or projection on anti-friction rolling elements 28. For this purpose an enlarged and concentric cylindrical surface as; at 200 is provided for the rollers 20. The thrust surface 20c will be thus concentric with the bore 20d. It will be noted that for the operation of head 20 during the suction period the thrust roller 3| will engage the remaining portion of bore 20d, after the provision -oi. enlarged concentric bore 200.

Large thrustrollers as at 3| are provided for ,,thrust loads between the driving heads 20 and the rotating floating support 32 as shown in Fig. 1. It will be noted that the thrust rollers 3| are engaged throughout the entire lengths of the roller with the support for rolling reciprocation and for primary load transmission therebetween. Each pin 3| is further provided with secondary reduced portions as at 35a for the purpose hereinafter to be described. The unitary floating support 32 is provided with slight radial shoulders as at 32a in order to receive secondary supports 23-23 respectively. Each of the secondary'supports 29 isrigidly secured at the respective-ends of the main support 32 by appropriate means such as press flt or the like. A slight radial c shoulder of the secondary support 23 as at 23a will be pressed against the coacting radial shoulder 32a of the main support 32. A

Each secondary support 23 is further provided with normally aligned continuous circular grooves 5 as at 30in such a manner that the reduced ends- 3| a of thrust pins or rollers 3| will be received therein. The assembly of the pin 3| will be such that for the primary thrust load 3| will be always positively supported by the main support" 70 outwardly. and will not be hindered in this respect by the reduced ends 31a. Furthermore the reduced ends 3la for the secondary pins will be assembled inthe grbove ways 30-40 invsu'ch a manner that a positive contact between the' pin ends and the working sides of the groove during suction stroke will have positive contact and coaction with the rings 29. Thus simultaneously, the large portion 3| of the thrust pin will be in positive thrust engagement with the inner surface of the main support 32, whereasthe pin ends 3m 5 will have positive engagement with the inner working surfaces of the thrust grooves 30-30. The outer faces of the thrust grooves 30-30 thus will have slight operating clearance for the pin ends to allow both positive coaction between the 0 primary and secondary supports and the primary and secondary thrust means respectively.

I The main support 32 is formed with slight circumferential recess to the extent of the entire lengths of rollers 34. Cage member 33 will en- 15 gage the rollers for frictionless rolling cooperation. A stationary support as at 36 will engage the rollers 34 in such a manner that the main support 32, the interposed rollers 34, and the sta- "tionary member 36, will form in assembly an '20 efllcient complete bearing assembly. The complete bearing assembly will be provided with -stroke adjustingand guide means as at 35 and 3'! in order to change the stroke of the piston and the delivery of the pump. 25

The stationary support 36 is provided with conventional parallel guiding and supporting bearing surfaces in coaction with the pump housing not shown in the figures. During stroke adjustment the entire piston actuating assembly in- 30 cluding a rotary and stationary support will be shifted parallel with itself to various positions of eccentricity in order to impart variable stroke and variable delivery to the pump. It will be noted that it is important that during the shift- 35 ing operation a strictly translatory motion be performed on the reactance assembly in order to keep the axis of the thrust rollers 3| parallel with the moving axis of the reactance as well as with thestationary axis of pintle and cylinder barrel. If the axis of the reactance during shifting operation remains not parallel with the axis of the pintle and, barrel it is obvious that the driving head 20 will not function properly and undue transverse forces and wear will be imposed 5 on the driving heads and their associated guide ways, which are primarily directed by the coacting flange I6 and its axis of rotation which is coincident with the axis of pintle and barrel respectively.

Various changes may be made in the embodiment of the pump hereinabove specifically described without departing from or sacrificing the advantages of the invention. as defined in the appended claims.

I claim:

1. In a rotary radial piston pump or motor, a rotatable barrel, a radial flange on the barrel, radial cylinders in the barrel in the zone of the flange, radial guideways in the flange respective to the cylinders,a valve pintle in valving cooperation with the cylinders, pistons in the cylinders respectively, a rotary reactance surrounding the cylinders and pistons, and means operatively connecting the rotary reactance to the pistons for actuation of the pistons upon concurrent rotation of the barrel and reactance rotor, said means comprising heads for the pistons respecgrooves respectively, each element having a central load transmission portion of its peripheral surface in direct rolling load transmitting contact with said reactance and a diametrically aligned opposite load transmitting peripheral surface portion and having two adjacent secondary portions positioned circumferentially between the first portions and engaged by portions of the wall of the associated groove for actuating the pistons during the suction stroke, an arcuate recess in the base of each groove and terminating intermediate the circumferential limits of the groove, and free anti-friction rollers in each recess between said diametrically aligned opposite load transmitting peripheral surface portion of the rolling element and the bottom of the recess for efiecting anti-friction load transmission between the said rolling element and the associated piston head, and antifriction means supporting said rotary reactance directly in the zone of the said rolling elements.

2. In a rotary radial piston pump or motor, a rotatable barrel, a radial flange on the barrel, radial cylinders in the barrel in the zone of the flange, radial guideways in the flange respective to the cylinders, a valve pintle in valving cooperation with the cylinders, pistons in the cylinders respectively, a reactance surrounding the cylinders and pistons, and means operatively connecting the reactance to the pistons for actuation of the pistons upon relative rotation of the barrel and reactance, said means comprising heads for the pistons, respectively reciprocable in said radial guideways, each of said heads having a transverse arcuate groove extending transversely of the associated head and open toward the reactance, cylindrical rolling elements rotatable in said grooves respectively and having their axes of rotation substantially parallel with the axis of rotation of the barrel, each element having a portion of its peripheral surface in direct rolling contact with said reactance at the open portion of the groove and a diametrically aligned opposite load transmitting peripheral surface portion, and having two adjacent secondary portions positioned circumferentially be: tween the first portions andengaged by the portions of the wall of the associated groove for actuating the associated piston during the suction stroke, an arcuaterecess in the base of each groove and terminating intermediate the circumferential limits of the groove, and free antifriction rollers in each recess between said diametrically aligned opposite load transmitting peripheral surface portion of the rolling element and the bottom of the recess for eflecting antifriction load transmission between the said rolling element and the associated piston head.

ELEK BENEDEK. 

